DVA-C02 Troubleshooting and Optimization Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  Increase the EC2 instance size to a larger type.

  Why it's wrong here

  Increasing the EC2 instance size primarily provides more compute resources, such as CPU, memory, and potentially network bandwidth *within* the instance. While this can improve the application's processing speed and ability to handle more requests concurrently, it does not directly address network latency caused by the physical distance between the user and the server, or the overhead of establishing network connections. Latency is often dominated by network propagation delay, not server processing time, unless the instance is severely under-provisioned and experiencing CPU/memory bottlenecks.

• ✓

  Use Amazon CloudFront as a content delivery network.

  Why this is correct

  Amazon CloudFront, a global content delivery network (CDN), significantly reduces latency by caching static and dynamic content at edge locations worldwide. When a user requests content, CloudFront serves it from the nearest edge location, minimizing the physical distance data must travel. This reduces the round-trip time (RTT) between the user and the content source, resulting in faster load times and an improved user experience compared to fetching all content directly from the origin server in a single AWS region.

• ✗

  Disable keep-alive connections on the ALB.

  Why it's wrong here

  Disabling keep-alive connections (also known as persistent connections) on the Application Load Balancer (ALB) would force a new TCP three-way handshake for every HTTP request. This constant connection establishment and teardown introduces significant overhead, consuming more network resources and increasing the overall latency per request. Keep-alive connections are designed to reuse an existing TCP connection for multiple requests, thereby reducing latency by eliminating repetitive setup costs. Therefore, disabling them would worsen, not reduce, latency.

• ✗

  Use multiple Availability Zones for the ALB.

  Why it's wrong here

  Deploying an Application Load Balancer (ALB) across multiple Availability Zones (AZs) primarily enhances fault tolerance and high availability. If one AZ experiences an outage, traffic can seamlessly failover to healthy targets in other AZs. However, this configuration does not inherently reduce network latency for individual user requests, as the ALB still operates within a specific AWS region, and users' physical distance to that region remains unchanged. Latency reduction typically involves moving content closer to the user geographically.

• ✓

  Enable HTTP/2 on the Application Load Balancer.

  Why this is correct

  Enabling HTTP/2 on the Application Load Balancer (ALB) significantly reduces latency by allowing multiple requests and responses to be multiplexed over a single TCP connection. Unlike HTTP/1.1, which often requires multiple connections or suffers from head-of-line blocking, HTTP/2 streams requests concurrently, minimizing connection setup overhead and improving resource utilization. This results in faster page loads, especially for web applications that fetch many small assets, as it avoids the latency associated with establishing new connections for each resource.

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